This Christmas: For The Concerned Eco-Worrier Who Has Everything….

They are in the vanguard of a push by the Marine Stewardship Council encouraging zoos to follow retailers and restaurants in using only sources it has certified as sustainable.

Providing there's no animal welfare issues - and I'd hope the zoo staff wouldn't do anything stupid like join up to this scheme if that was the case, but you never know - you might ask, 'Why not?'...

Uncertified herring are no longer disappearing down the throats of Sofus and Miranda, the zoo's sea lions. They have been replaced by MSC-approved stocks from Scottish waters. The zoo's 200 penguins will be soon guzzling certified South African hake instead of blue whiting from the Pacific if trials prove them a suitable substitute.

And when that starts to run out? Tofu?

Darren McGarry, animal collection manager for the zoo, said: "We're really pleased that the Patagonian sea lions have taken to their new feed. Zoo animals can be very picky about what they eat but they've taken to the MSC-certified feeds straight away."